/Engine/Plugins/Experimental/FullBodyIK/Source/PBIK/Public/Core/PBIKBody.h
For sorting Bodies hierarchically (root to leaf order)
namespace PBIK { bool PBIK::operator< ( const [FRigidBody](API\Plugins\PBIK\Core\FRigidBody) & Lhs, const [FRigidBody](API\Plugins\PBIK\Core\FRigidBody) & Rhs ) }